|Publication number||US5457394 A|
|Application number||US 08/058,398|
|Publication date||Oct 10, 1995|
|Filing date||May 7, 1993|
|Priority date||Apr 12, 1993|
|Also published as||CA2162257A1, CA2162257C, DE69425373D1, DE69425373T2, EP0700528A1, EP0700528A4, EP0700528B1, US5512834, WO1994027168A1|
|Publication number||058398, 08058398, US 5457394 A, US 5457394A, US-A-5457394, US5457394 A, US5457394A|
|Inventors||Thomas E. McEwan|
|Original Assignee||The Regents Of The University Of California|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (8), Non-Patent Citations (4), Referenced by (213), Classifications (46), Legal Events (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.
This application is a continuation-in-part (CIP) of Serial No. 08/044,745, filed Apr. 12, 1993, now U.S. Pat. No. 5,345,471, issued Sep. 6, 1994.
This invention relates generally to sensors for locating hidden objects and more particularly to sensors for locating wall studs.
A common problem faced by anyone attempting to hang a picture or cabinet is how to precisely locate between-wall studs so a sturdy hook may be attached or clearance may be provided for the cabinet. Since wall studs are usually covered by sheetrock or wallboard and finished-off, stud location is not visible. A similar problem arises when hanging plants and lamps from the ceiling, or when nailing down squeaky floorboards and stair steps.
General methods for locating studs and joists include tapping with a hammer, searching for nails with a magnetic compass, and random piercing with a nail. Hammer tapping and magnetic compass searching are unreliable and time-consuming, and random piercing is destructive. Once a nail is located, it may be off-center. Also, the stud may be warped, making it impossible to deduce accurate stud location at any distance from the nail.
These primitive methods were vastly advanced when an electronic wall stud sensor became commercially available about ten years ago. The user places the sensor flat against the wall and scans it laterally across the extent of the wall. When it passes over a stud, a vertical series of LEDs light to indicate the presence of the stud behind the wall. The sensor is based on dielectric density sensing. U.S. Pat. No. 4,099,118 describes a portable electronic wall stud sensor having capacitor plates and circuitry for detecting changes in the capacitive charge due to changes in the dielectric constant in the wall adjacent the sensor. U.S. Pat. No. 4,464,622 describes a similar capacitive sensor with calibration means and means for detecting an AC line in the wall.
Dielectric density sensing has limitations. If a small air gap forms between the sensor and the wall, the device becomes inoperative due to the substantial change in density adjacent the two sensing plates that are internal to the unit. It is therefore difficult or impossible to locate studs on rough or highly textured surfaces.
Another limitation is that stud detection is directly affected by the dielectric constant of the intervening wall material. Sheetrock, plywood, particle board, and dense hardwoods vary in dielectric constant to such an extent that a dielectric sensor generally only works on sheetrock and not on plywood walls, wood floors, stair steps, furniture or cabinetry.
Accordingly it is an object of the invention to provide an improved stud finder or other hidden object locator.
It is another object of the invention is to provide a stud finder or other hidden object locator that is not based on capacitive measurements of change in dielectric constant.
The invention is an impulse radar studfinder which transmits a sequence of short impulses, without a carrier, and detects the reflected impulses after a fixed time period representing a fixed range. A large number of pulses are averaged, or integrated, to produce an output signal. The presence of hidden objects, e.g. wall studs, behind the wall produces the reflected pulses.
FIG. 1 is a block diagram of the impulse radar studfinder.
FIG. 2 is a timing diagram of the impulse radar studfinder.
FIG. 3 illustrates the range gate location and reflection mechanism.
FIGS. 4A-D illustrate pulse shaping for off-surface invariance.
FIG. 4A shows the preferred pulse shape with a unipolar peak and exponential tail while FIG. 4B shows a post shoot or ringing pulse. FIGS. 4C, D show the resulting indicator signals.
FIG. 5 shows a wire antenna configuration for the studfinder.
FIG. 6 is a schematic diagram of the impulse radar studfinder.
The sensor is based on the pulse-echo radar principle of clocking the two-way time of flight of an electromagnetic pulse. It is called impulse radar because an unmodulated, "video", or baseband pulse is radiated rather than the usual sinusoidal burst found in conventional radar. The pulses are just a sequence of impulses; there is no carrier. There is no specific frequency associated with this radar; rather, its frequency spectrum is related by the Fourier transform of the pulse. The free-space radiated pulse is a Gaussian-shaped impulse about 200 picoseconds wide. A major advantage to impulse radar is that its spectrum is located as close to DC as possible, where materials attenuation is the lowest.
Operation is based on emitting a pulse from a transmit antenna, waiting for a brief period of time corresponding to about 2 inches of round trip time of flight at the speed of light, and then opening a gate connected to a receive antenna to allow the reflected pulse to be sampled. This process is repeated at a 1 MHz rate, allowing approximately 10,000 receive pulses to be averaged prior to driving a signal intensity display.
The high level of averaging reduces the random noise accompanying the sampled signal to such an extent that extremely low amplitude signals can be detected. Repetitive operation also leads to extreme simplification of the entire circuit.
The invention utilizes an impulse radar ultra-wideband receiver as described in U.S. Pat. application Ser. No. 08/044,745 filed Apr. 12, 1993, now U. S. Pat. No. 5,345,471issued Sep. 6, 1994, by Thomas E. McEwan entitled "Ultra-Wideband Receiver," which is herein incorporated by reference.
A block diagram of the sensor is given in FIG. 1. Pulses from a 1 MHz pulse repetition frequency (PRF) or pulse repetition interval (PRI) generator 10 are input into two parallel paths, transmit path 12 and receive or gating path 14. In the transmit path 12, PRF/PRI generator 10 drives a step generator 16, which provides a transmit pulse with a +5 to 0 volt, 200 ps transition that is applied to the transmit antenna (T) 18. The electrical length of the antenna is set to be short relative to the spectral content of the voltage step, so differentiation occurs in the antenna and a 200ps wide impulse is radiated. In effect, the antenna is shorter than a half wavelength of the highest frequency component in the voltage step.
The receive antenna (R) 20 picks up the reflected impulse from stud 22 behind wall board 24 and applies it to a sample/hold (S/H) circuit 26 that is gated by a pulse from gating path 14 that is delayed approximately 0.5 ns from the time that the transmit antenna radiates the impulse. Pulses from PRF/PRI generator 10 which are input into transmit path 12 are simultaneously input into gating path 14 where they pass through range delay generator 30 followed by step generator 32 which produces a 200 ps gating pulse which controls gating switch 34. Delay generator 30 is set at about 0.5 ns so that the impulse radar range is about 1-2". The gating pulse closes switch 34 so that reflected pulses from the 1-2" range are input into sample/hold circuit (S/H) 26. The S/H circuit 26 is formed of a capacitor 28 connected to ground. Reflections, or lack thereof, occurring 1-2" from the antennas 18, 20 are thereby sampled. The size of the capacitor 28 in the sample/hold 26 circuit is sufficiently large that each sample only partially charges it, and approximately 10,000 samples are required for the circuit to reach an equilibrium with the receive antenna signal. The product of the impedance of the receive antenna 20 and the capacitance of capacitor 28 yield a time constant which is much greater than the width of the gate pulse, so it takes many pulses to charge capacitor 28.
The timing relationship is shown in FIG. 2. The five waveforms-are shown over one pulse repetition interval. The transmit step generator produces a +5 V to 0 V, 200 ps step, which produces a 200 ps wide radiated impulse from the transmit antenna. The reflected pulse from the receive antenna coincides with the gating pulse. Each received pulse produces an incremental voltage change ΔV on the capacitor of the S/H circuit. The capacitor voltage is the output of the averaging S/H circuit. The increment ΔV=1/N of the total received pulse where N is the number of samples averaged, typically about 10,000.
The noise voltage at the sample/hold circuit is reduced by a factor related to the square root of the number of samples averaged, 100× in this case, and by a factor related to the effective time constant of the averaging circuit relative to the PRI of the system and the instantaneous bandwidth of the sampler--a factor stemming from the sampled data nature of the sample/hold circuit. In all, greater than 60 dB noise reduction is obtained compared to a circuit with 2 GHz bandwidth, i.e., the bandwidth of the radiated pulse.
The sample/hold output is applied to the voltage summation element 36 in FIG. 1, which subtracts background reflections as described herein. The output of the summer 36 is amplified by amplifier (A) 38, typically 60 dB across a passband of DC-16 Hz, and applied to an indicator circuit 40. The indicator circuit 40 may consist of a linear arrangement of LEDs 42 that sequentially light in proportion to the applied voltage, which is linearly related to the reflection magnitude of the electromagnetic impulse.
The display circuit begins to respond at a level corresponding to approximately 100 microvolts appearing at the receive antenna terminal. Since systematic errors in the sample/hold circuit, the summer, and amplifier may amount to several tens of millivolts, this error must be subtracted out in order to detect a 100 microvolt change caused by a distant stud. In addition, front surface reflections from the wall contribute to the error voltage.
Therefore, when power is applied to the unit, a "power-on" detection (reset) circuit 44 closes the "calibrate" switch 46 for one second so the integrator 48 in the feedback path 50 of amplifier A servo's the output of amplifier A until an equilibrium is reached: the output of A is forced to equal the reference voltage applied to the integrator. Since integrators have extremely high DC gain, the voltage difference between the output of A and the reference is reduced to a negligible value. The display is also referenced to the same reference voltage as the integrator, so the indicator scales its response relative to the voltage deviation from the reference voltage. This power-on calibrate sequence leaves the unit ready to respond to changes in voltage caused only by a change in the impulses reflected off the wall or a stud.
FIG. 3 depicts the geometry of the antennas and the effective physical location of the sample/hold gate as its position in time relative to the transmit pulse is projected into an equivalent position in space and scaled by the square root of the relative dielectric constant of the intervening building material (εr ˜2-3). As shown in a top view, transmit antenna (T) 18 and receive antenna (R) 20 in studfinder housing 52 are positioned adjacent wall 24 and operate with a range gate 54 determined by the delay generator 30 (FIG. 1). The range gate typically extends about 1 inch behind the wall. The range gate is actually curved because of the spherical waves emitted by antenna T. However, over small distances, the range gate is approximately linear (as shown in FIGS. 4A,B).
The propagation impedance in free space ##EQU1## where μo is the permeability of a vacuum and εo is the permittivity of a vacuum. The propagation impedance in a material (wood) having ##EQU2## The free space propagation impedance is 377 ohms and the propagation impedance of wood (Εr =2) is 266 ohms. This difference in impedance causes a difference in the reflection magnitude when a stud is present. A profile of the propagation impedance Zo in the range gate location 54 is shown in FIG. 3.
In a one dimensional analogy to propagation along a transmission line, which can be equated to time domain reflectometry (TDR), reflections off a stud become equivalent to reflections from a transmission line discontinuity. The reflection coefficient, F, defined as (Y-1)/(Y+1) where Y=Z(wall)/Z(space), can be applied to determine what fraction of the radiated pulse is returned.
For example, if the wall material is wood with an εr =2, the reflection magnitude, relative to 377 ohms, is 0.17. When a wood stud is behind the wood wall, no reflection occurs since there is no change in propagation impedance. Thus the difference in reflection magnitude between the presence and absence of a stud is 0.17. If the stud were metal, the reflection would be total, or 1.0. Thus, metal is easily discerned from wood by a 5.9× greater reflection magnitude. Even if the metal has a much smaller cross-section, as may be the case with a wire, it is still easily discerned in practice as long as the polarization of the wire and the studfinder antenna match--which is generally the case for wires behind walls and for a vertical orientation of the studfinder.
This invention overcomes a serious limitation stemming from a variable reflection magnitude from the first surface 25 of the wallboard. The circuit loses its power-on calibration if the sensor is moved from the wall by even the slightest distance "x" in FIG. 4A. Once out of calibration, reliable detection of a stud is compromised. It is most desirable that the indicated reflection amplitude from the wallboard remain constant over a housing-to-wall distance of several inches.
The problem of varying first surface reflection magnitude is caused by radiating a pulse, shown in FIG. 4B, that contains either post-shoot or ringing--a common effect when radiating ultra-wideband pulses through an antenna. What radiates later in time falls into the sampler's gate when reflected off objects closer than the intended range gate 54, i.e. there is a displaced range gate 54x. Accordingly, ringing components reflect off the front surface of the wall and fold into the reflections from the stud in simultaneity. Indeed, these front surface reflections can exceed the rear surface reflections. During power-on calibration, the front surface reflections are subtracted out, so the unit can properly detect a stud--until the unit is lifted slightly off the surface and the calibration is altered by changes in front surface reflections. Thus the sensor has little tolerance for rough surfaces or non-contact operation. Because of changing polarity of the pulse, the indicator signal can change polarity, as shown in FIG. 4C.
The solution for this problem is indicated in FIG. 4A by the radiated waveform, which has an exponential tail of the same voltage polarity as its peak voltage. If the peak of the pulse is spatially located behind the wall for stud detection, the center of the tail may then be spatially located at the front surface of the wall. When the calibrated studfinder is lifted from the wall (increase "x"), the diminishing surface return--caused by increasing distance--is compensated by the increasing tail amplitude that becomes positioned at the wall front surface. FIG. 4D shows the indicator signal (amplified reflection signal) for the tailpulse case, showing a constant signal over a 2" variation in "x". Thus in the preferred embodiment, the studfinder emits a pulse having the waveform shown in FIG. 4A. This can easily be done by proper design of the transmit antenna.
FIG. 5 is a sketch of the preferred configuration of the antennas. The antennas T, R are simple wires 56, 58 situated above a ground plane 60 and may be considered to be either leaky transmission lines or bent monopoles. Resistors RT are distal termination resistors that are set higher than the characteristic impedance of the lines. The value of RT affects the shape of the tail pulse, so RT can be fine-tuned to obtain a flat response characteristic versus distance from the wall surface.
In an illustrative embodiment, the ground plane is a copper ground plane circuit board. The antennas are #24 AWG enameled copper wire. Each antenna has a length L of 1.5" and a height H of 0.8".
The transmit antenna T is driven by a voltage step so its radiated waveform tends to be an impulse with a slight tail caused by the distal reflection from RT, which is set to be higher than the propagation impedance of the 1.5" wire. A similar effect occurs at the receive antenna R, where there is no termination at the sample/hold input. The combination of high impedance and parasitic capacitance at the sample/hold input tend to integrate the receive pulse, further stretching the tail of the pulse. The propagation impedance of the 1.5" wire is about 200 ohms, and the value of RT is about 330 ohms.
FIG. 6 shows a prototype embodiment of the studfinder. The PRI generator 62 is formed of three inverters (I1) and is followed by a pulse width limiter 64. The pulses pass through buffers (I1) to step generator 66 formed of a low cost TV tuner transistor Q1=BFW92, whose output is connected to transmit antenna 68 which is a wire loop. The pulses from PRI generator 62 also follow a second path through range delay generator 70 which is formed of a variable resistance plus stray capacitance and input capacitance of a buffer gate. The delayed pulse is input into step generator 72, formed of another transistor Q2=BFW92, which produces the gating pulse. Reflected signals are picked up by receive antenna 74 and input into S/H circuit (capacitor) 76 which is gated by the gating pulse through Schottky diode D1=MBD701. The output from S/H circuit 76 is input into amplifier 78 (I2). A second amplifier 80 (I2) is connected though calibrate switch (MOSFET) Q3 (part of I3) from the output of amplifier 78 back to its input to form the baseline subtractor/integrator circuit. The "power on" reset circuit 82 (I3) turns on transistor Q3 so that the output of amplifier 78 is fed back through operational amplifier 80 to subtract the background from the input of amplifier 78. The input of amplifier 78 serves as the summation element for the S/H circuit 76 output and the calibrate signal from amplifier 80. The output of amplifier 78 drives the indicator circuit 84 which is formed of a plurality of comparators (I4) referenced to different levels which drive associated LED's. The highest level LED "metal" is turned on by comparator (I5); the high reflectivity of metal produces a high indicator signal. A low battery test circuit 86 (I5) and voltage regulator circuit 88 (16) are also included. In a preferred embodiment, I1=74HC04, I2=TLC27L2, I3=CD4007, I4=LM324, I5=LM358, and I6=78L05.
The impulse radar studfinder of this invention propagates an electromagnetic pulse, and since electromagnetic propagation scales by the square root of dielectric constant, the radar studfinder is substantially independent of building materials. Further, the propagating pulse will easily radiate across an air gap of several inches. The sensitivity of this invention is such that a stud can be detected behind several inches of concrete with the unit held an inch off the surface of the concrete (˜40 dB signal-to-noise ratio). The studfinder can similarly be applied to locate other hidden objects.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3102232 *||Jun 17, 1960||Aug 27, 1963||North American Aviation Inc||Microwave electrical thickness comparator utilizing a waveguide probe|
|US4008469 *||Aug 6, 1974||Feb 15, 1977||Terrestrial Systems, Incorporated||Signal processing in short-pulse geophysical radar system|
|US4023154 *||Apr 9, 1976||May 10, 1977||Willie George Comeaux||Apparatus for detecting location of metal cable failure|
|US4057708 *||May 10, 1976||Nov 8, 1977||Motorola Inc.||Minimum miss distance vector measuring system|
|US4072942 *||Nov 11, 1976||Feb 7, 1978||Calspan Corporation||Apparatus for the detection of buried objects|
|US4099118 *||Jul 25, 1977||Jul 4, 1978||Franklin Robert C||Electronic wall stud sensor|
|US4132943 *||Apr 18, 1977||Jan 2, 1979||Mobile Oil Corporation||Remote sensing of hydrocarbon gas seeps utilizing microwave energy|
|US4464622 *||Mar 11, 1982||Aug 7, 1984||Franklin Robert C||Electronic wall stud sensor|
|1||Ludien, Jerry R. "Terrain Analysis by Electromagnetic Means; Radar Responses to Laboratory Prepared Samples"; U.S. Army Engineer Waterways Experiment Station Corps of Engineers, Technical Report No. 3-693, Report 2, pp. III-IV and 1-23, Sep. 1966.|
|2||*||Ludien, Jerry R. Terrain Analysis by Electromagnetic Means; Radar Responses to Laboratory Prepared Samples ; U.S. Army Engineer Waterways Experiment Station Corps of Engineers, Technical Report No. 3 693, Report 2, pp. III IV and 1 23, Sep. 1966.|
|3||*||S.V.B; news Ground piercing radar aims at commercial market, Microwaves Dec. 1973, p. 12.|
|4||S.V.B; news Ground-piercing radar aims at commercial market, Microwaves Dec. 1973, p. 12.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5519400 *||Jun 6, 1995||May 21, 1996||The Regents Of The University Of California||Phase coded, micro-power impulse radar motion sensor|
|US5581256 *||Jun 6, 1995||Dec 3, 1996||The Regents Of The University Of California||Range gated strip proximity sensor|
|US5651286 *||Jul 23, 1996||Jul 29, 1997||Teleflex Incorporated||Microprocessor based apparatus and method for sensing fluid level|
|US5656774 *||Jun 4, 1996||Aug 12, 1997||Teleflex Incorporated||Apparatus and method for sensing fluid level|
|US5752783 *||Feb 20, 1996||May 19, 1998||Blaw-Knox Construction Equipment Corporation||Paver with radar screed control|
|US5757320 *||Dec 17, 1996||May 26, 1998||The Regents Of The University Of California||Short range, ultra-wideband radar with high resolution swept range gate|
|US5854603 *||Jun 3, 1997||Dec 29, 1998||Zircon Corporation||Ultra-wideband swept range gate radar system with variable transmitter delay|
|US5883591 *||Feb 27, 1998||Mar 16, 1999||The Regents Of The University Of California||Ultra-wideband impedance sensor|
|US5896102 *||Jul 28, 1997||Apr 20, 1999||Zircon Corporation||Swept range gate radar system for detection of nearby objects|
|US5901633 *||Nov 27, 1996||May 11, 1999||Case Corporation||Method and apparatus for sensing piston position using a dipstick assembly|
|US5905455 *||Oct 23, 1997||May 18, 1999||Zircon Corporation||Dual transmitter visual display system|
|US5943908 *||Sep 8, 1997||Aug 31, 1999||Teleflex Incorporated||Probe for sensing fluid level|
|US5977778 *||Nov 27, 1996||Nov 2, 1999||Case Corporation||Method and apparatus for sensing piston position|
|US5978749 *||Jun 30, 1997||Nov 2, 1999||Pile Dynamics, Inc.||Pile installation recording system|
|US5986579 *||Jul 31, 1998||Nov 16, 1999||Westinghouse Air Brake Company||Method and apparatus for determining railcar order in a train|
|US6005395 *||Nov 12, 1997||Dec 21, 1999||Case Corporation||Method and apparatus for sensing piston position|
|US6067673 *||Jul 17, 1998||May 30, 2000||Kohler Company||Bathroom fixture using radar detector having leaky transmission line to control fluid flow|
|US6114974 *||Aug 25, 1999||Sep 5, 2000||Wabtec Railway Electronics||Method and apparatus for determining railcar order in a train|
|US6128558 *||Jun 9, 1998||Oct 3, 2000||Wabtec Railway Electronics, Inc.||Method and apparatus for using machine vision to detect relative locomotive position on parallel tracks|
|US6142059 *||Dec 18, 1998||Nov 7, 2000||Case Corporation||Method and apparatus for sensing the orientation of a mechanical actuator|
|US6166546 *||Sep 13, 1999||Dec 26, 2000||Atlantic Richfield Company||Method for determining the relative clay content of well core|
|US6177903||Jun 14, 1999||Jan 23, 2001||Time Domain Corporation||System and method for intrusion detection using a time domain radar array|
|US6188228 *||Nov 6, 1998||Feb 13, 2001||Harald Philipp||Hammer having integral stud and mains sensor|
|US6191724 *||Jan 28, 1999||Feb 20, 2001||Mcewan Thomas E.||Short pulse microwave transceiver|
|US6206340||Jul 17, 1998||Mar 27, 2001||Kohler Company||Radar devices for low power applications and bathroom fixtures|
|US6208246||Jul 31, 1998||Mar 27, 2001||Wabtec Railway Electronics, Inc.||Method and apparatus for improving railcar visibility at grade crossings|
|US6211662||Aug 7, 1998||Apr 3, 2001||The Stanley Works||Hand-held hidden object sensor for sensing a location of objects hidden behind a surface of an architectural structure|
|US6215293 *||Aug 12, 1998||Apr 10, 2001||Solar Wide Industrial Limited||Portable stud detector for detecting wood, metal, and live wires|
|US6218979||Jun 14, 1999||Apr 17, 2001||Time Domain Corporation||Wide area time domain radar array|
|US6229999 *||Mar 31, 1998||May 8, 2001||Hollandse Signaalapparaten B.V.||Receiver system|
|US6239736||Oct 29, 1999||May 29, 2001||Interlogix, Inc.||Range-gated radar motion detector|
|US6243036||Jul 2, 1999||Jun 5, 2001||Macaleese Companies, Inc.||Signal processing for object detection system|
|US6250601||Jul 17, 1998||Jun 26, 2001||Kohler Company||Advanced touchless plumbing systems|
|US6273521||Jul 31, 1998||Aug 14, 2001||Westinghouse Air Brake Technologies Corporation||Electronic air brake control system for railcars|
|US6279173||Apr 12, 1999||Aug 28, 2001||D2M, Inc.||Devices and methods for toilet ventilation using a radar sensor|
|US6340139||Jun 1, 2000||Jan 22, 2002||Labarge, Inc.||Highway grade crossing vehicle violation detector|
|US6342696||May 25, 1999||Jan 29, 2002||The Macaleese Companies, Inc.||Object detection method and apparatus employing polarized radiation|
|US6351246||May 3, 2000||Feb 26, 2002||Xtremespectrum, Inc.||Planar ultra wide band antenna with integrated electronics|
|US6359582||Sep 16, 1997||Mar 19, 2002||The Macaleese Companies, Inc.||Concealed weapons detection system|
|US6360998||Jun 9, 1998||Mar 26, 2002||Westinghouse Air Brake Company||Method and apparatus for controlling trains by determining a direction taken by a train through a railroad switch|
|US6377201||Jun 3, 1998||Apr 23, 2002||Science Applications International Corporation||Radar and method therefor|
|US6377215||Jun 9, 1998||Apr 23, 2002||Wabtec Railway Electronics||Apparatus and method for detecting railroad locomotive turns by monitoring truck orientation|
|US6388609||Mar 26, 2001||May 14, 2002||Kohler Company||Radar devices for low power applications and bathroom fixtures|
|US6400307||Jan 23, 2001||Jun 4, 2002||Time Domain Corporation||System and method for intrusion detection using a time domain radar array|
|US6417797||Jun 1, 1999||Jul 9, 2002||Cirrus Logic, Inc.||System for A multi-purpose portable imaging device and methods for using same|
|US6512474||May 23, 2001||Jan 28, 2003||Lockhead Martin Corporation||Ultra wideband signal source|
|US6552677||Feb 26, 2002||Apr 22, 2003||Time Domain Corporation||Method of envelope detection and image generation|
|US6568655||Mar 4, 2002||May 27, 2003||Kohler Company||Radar devices for low power applications and bathroom fixtures|
|US6573857||Apr 25, 2002||Jun 3, 2003||Time Domain Corporation||System and method for intrusion detection using a time domain radar array|
|US6588313||Nov 19, 2001||Jul 8, 2003||Rosemont Inc.||Hydraulic piston position sensor|
|US6590545||Jan 25, 2002||Jul 8, 2003||Xtreme Spectrum, Inc.||Electrically small planar UWB antenna apparatus and related system|
|US6593754 *||Mar 29, 2000||Jul 15, 2003||Actuant Corporation||Compact subsurface object locator|
|US6626038||Jun 18, 1999||Sep 30, 2003||Magnetrol International Inc.||Time domain reflectometry measurement instrument|
|US6640629||Mar 21, 2002||Nov 4, 2003||Magnetrol International Inc.||Time domain reflectometry measurement instrument|
|US6661367 *||Mar 14, 2002||Dec 9, 2003||International Business Machines Corporation||Non-destructive probing system and a method thereof|
|US6667724||Nov 30, 2001||Dec 23, 2003||Time Domain Corporation||Impulse radar antenna array and method|
|US6690320 *||Jun 11, 2001||Feb 10, 2004||Magnetrol International Incorporated||Time domain reflectometry measurement instrument|
|US6700939||Dec 11, 1998||Mar 2, 2004||Xtremespectrum, Inc.||Ultra wide bandwidth spread-spectrum communications system|
|US6710736||Jun 2, 2003||Mar 23, 2004||Time Domain Corporation||System and method for intrusion detection using a time domain radar array|
|US6722260||Dec 11, 2002||Apr 20, 2004||Rosemount Inc.||Hydraulic piston position sensor|
|US6722261||Dec 11, 2002||Apr 20, 2004||Rosemount Inc.||Hydraulic piston position sensor signal processing|
|US6725731||Nov 6, 2002||Apr 27, 2004||Rosemount Inc.||Bi-directional differential pressure flow sensor|
|US6735879||May 7, 2002||May 18, 2004||Irwin Industrial Tool Company||Laser line generating device|
|US6738044||May 31, 2001||May 18, 2004||The Regents Of The University Of California||Wireless, relative-motion computer input device|
|US6789458||Dec 12, 2002||Sep 14, 2004||Rosemount Inc.||System for controlling hydraulic actuator|
|US6817252||Dec 12, 2002||Nov 16, 2004||Rosemount Inc.||Piston position measuring device|
|US6825456||Jan 29, 2002||Nov 30, 2004||Safe Zone Systems, Inc.||Signal processing for object detection system|
|US6842993||Apr 11, 2003||Jan 18, 2005||Dimauro Robert T.||Utility box template|
|US6844713||Jun 9, 2003||Jan 18, 2005||Actuant Corporation||Compact stud finder|
|US6848323||Dec 12, 2002||Feb 1, 2005||Rosemount Inc.||Hydraulic actuator piston measurement apparatus and method|
|US6856271||Jan 9, 2003||Feb 15, 2005||Safe Zone Systems, Inc.||Signal processing for object detection system|
|US6901112||Sep 30, 2002||May 31, 2005||Freescale Semiconductor, Inc.||Ultra wide bandwidth spread-spectrum communications system|
|US6906625||Feb 24, 2000||Jun 14, 2005||Time Domain Corporation||System and method for information assimilation and functionality control based on positioning information obtained by impulse radio techniques|
|US6906662||Mar 21, 2002||Jun 14, 2005||Magnetrol International, Incorporated||Time domain reflectometry measurement instrument|
|US6931078||Sep 30, 2002||Aug 16, 2005||Freescale Semiconductor, Inc.||Ultra wide bandwidth spread-spectrum communications systems|
|US6935034||Dec 11, 2003||Aug 30, 2005||Irwin Industrial Tool Company||Laser line generating device|
|US7013570||Jul 1, 2003||Mar 21, 2006||Irwin-Industrial Tool Company||Stud finder|
|US7088284 *||Nov 16, 2003||Aug 8, 2006||Preco Electronics, Inc.||Portable proximity-sensing safety device|
|US7095363||Mar 26, 2004||Aug 22, 2006||Fujitsu Limited||Pulse radar apparatus|
|US7116091 *||Mar 4, 2004||Oct 3, 2006||Zircon Corporation||Ratiometric stud sensing|
|US7134217||Mar 11, 2005||Nov 14, 2006||Gem Temp, Llc||Printing device including stud finder for installing gem electrical outlet box|
|US7148703||May 14, 2004||Dec 12, 2006||Zircon Corporation||Auto-deep scan for capacitive sensing|
|US7167123||Nov 24, 2004||Jan 23, 2007||Safe Zone Systems, Inc.||Object detection method and apparatus|
|US7170408||Jun 14, 2005||Jan 30, 2007||Time Domain Corporation||System and method for information assimilation and functionality control based on positioning information obtained by impulse radio means|
|US7193405||Jun 3, 2005||Mar 20, 2007||The Stanley Works||Electronic multi-depth object locator with self-illuminating optical element warning and detection|
|US7209523 *||Feb 17, 1999||Apr 24, 2007||Multispectral Solutions, Inc.||Ultra-wideband receiver and transmitter|
|US7269907||Jul 21, 2004||Sep 18, 2007||Irwin Industrial Tool Company||Laser line generating device with swivel base|
|US7278218||Jul 1, 2003||Oct 9, 2007||Irwin Industrial Tool Company||Laser line generating device with swivel base|
|US7358888||Mar 23, 2004||Apr 15, 2008||Time Domain||System and method for intrusion detection using a time domain radar array|
|US7408973||Jun 24, 2005||Aug 5, 2008||Freescale Semiconductor, Inc.||Ultra wide bandwidth spread-spectrum communications system|
|US7417581||Oct 31, 2007||Aug 26, 2008||Time Domain Corporation||System and method for intrusion detection using a time domain radar array|
|US7450052||May 12, 2006||Nov 11, 2008||The Macaleese Companies, Inc.||Object detection method and apparatus|
|US7474256 *||Aug 12, 2004||Jan 6, 2009||Sharp Kabushiki Kaisha||Position detecting system, and transmitting and receiving apparatuses for the position detecting system|
|US7482968 *||Apr 17, 2006||Jan 27, 2009||Hilti Aktiengesellschaft||Detector for embedded elongate objects|
|US7487596||Jun 25, 2004||Feb 10, 2009||Irwin Industrial Tool Company||Laser line projected on an edge of a surface|
|US7492165||Jul 27, 2006||Feb 17, 2009||Festo Ag & Co.||Position detecting device with a microwave antenna arrangement|
|US7506547||Jan 26, 2004||Mar 24, 2009||Jesmonth Richard E||System and method for generating three-dimensional density-based defect map|
|US7592944||Oct 31, 2007||Sep 22, 2009||Time Domain Corporation||System and method for intrusion detection using a time domain radar array|
|US7596242 *||Oct 5, 2006||Sep 29, 2009||Automotive Technologies International, Inc.||Image processing for vehicular applications|
|US7616676||Feb 11, 2008||Nov 10, 2009||Freescale Semiconductor, Inc.||Method and system for performing distance measuring and direction finding using ultrawide bandwidth transmissions|
|US7679546 *||Sep 20, 2007||Mar 16, 2010||Techtronic Power Tools Technology Limited||Apparatus and method of determining location of an object|
|US7711337||Jan 16, 2007||May 4, 2010||Paratek Microwave, Inc.||Adaptive impedance matching module (AIMM) control architectures|
|US7714676||Nov 8, 2006||May 11, 2010||Paratek Microwave, Inc.||Adaptive impedance matching apparatus, system and method|
|US7725150||Jun 4, 2003||May 25, 2010||Lifewave, Inc.||System and method for extracting physiological data using ultra-wideband radar and improved signal processing techniques|
|US7728693||Mar 17, 2008||Jun 1, 2010||Paratek Microwave, Inc.||Tunable microwave devices with auto-adjusting matching circuit|
|US7795990||Mar 17, 2008||Sep 14, 2010||Paratek Microwave, Inc.||Tunable microwave devices with auto-adjusting matching circuit|
|US7852170||Oct 10, 2008||Dec 14, 2010||Paratek Microwave, Inc.||Adaptive impedance matching apparatus, system and method with improved dynamic range|
|US7856882||Jul 2, 2008||Dec 28, 2010||Jesmonth Richard E||System and method for generating three-dimensional density-based defect map|
|US7865154||Oct 8, 2005||Jan 4, 2011||Paratek Microwave, Inc.||Tunable microwave devices with auto-adjusting matching circuit|
|US7873099||Oct 31, 2007||Jan 18, 2011||Time Domain Corporation||Time transfer using ultra wideband signals|
|US7917104||Apr 23, 2007||Mar 29, 2011||Paratek Microwave, Inc.||Techniques for improved adaptive impedance matching|
|US7969257||Mar 17, 2008||Jun 28, 2011||Paratek Microwave, Inc.||Tunable microwave devices with auto-adjusting matching circuit|
|US7991363||Nov 14, 2007||Aug 2, 2011||Paratek Microwave, Inc.||Tuning matching circuits for transmitter and receiver bands as a function of transmitter metrics|
|US8008982||Mar 11, 2010||Aug 30, 2011||Paratek Microwave, Inc.||Method and apparatus for adaptive impedance matching|
|US8067858||Oct 14, 2008||Nov 29, 2011||Paratek Microwave, Inc.||Low-distortion voltage variable capacitor assemblies|
|US8098707||Jan 31, 2007||Jan 17, 2012||Regents Of The University Of Minnesota||Ultra wideband receiver|
|US8125399||Jan 16, 2007||Feb 28, 2012||Paratek Microwave, Inc.||Adaptively tunable antennas incorporating an external probe to monitor radiated power|
|US8193802||Apr 9, 2009||Jun 5, 2012||Milwaukee Electric Tool Corporation||Slidably attachable non-contact voltage detector|
|US8213886||May 7, 2007||Jul 3, 2012||Paratek Microwave, Inc.||Hybrid techniques for antenna retuning utilizing transmit and receive power information|
|US8217731||Mar 11, 2010||Jul 10, 2012||Paratek Microwave, Inc.||Method and apparatus for adaptive impedance matching|
|US8217732||Mar 11, 2010||Jul 10, 2012||Paratek Microwave, Inc.||Method and apparatus for adaptive impedance matching|
|US8253619||Dec 1, 2009||Aug 28, 2012||Techtronic Power Tools Technology Limited||Electromagnetic scanning imager|
|US8264401||Apr 22, 2012||Sep 11, 2012||Sensys Networks, Inc.||Micro-radar, micro-radar sensor nodes, networks and systems|
|US8269683||May 13, 2009||Sep 18, 2012||Research In Motion Rf, Inc.||Adaptively tunable antennas and method of operation therefore|
|US8274273||Apr 9, 2009||Sep 25, 2012||Milwaukee Electric Tool Corporation||Test and measurement device with a pistol-grip handle|
|US8275572||Sep 25, 2012||The Boeing Company||Difference frequency detection with range measurement|
|US8284027||Sep 18, 2006||Oct 9, 2012||Brother Kogyo Kabushiki Kaisha||Position detecting system, responder and interrogator, wireless communication system, position detecting method, position detecting program, and information recording medium|
|US8289201 *||Jun 6, 2007||Oct 16, 2012||The Boeing Company||Method and apparatus for using non-linear ground penetrating radar to detect objects located in the ground|
|US8299867||Nov 8, 2006||Oct 30, 2012||Research In Motion Rf, Inc.||Adaptive impedance matching module|
|US8299924||Jun 6, 2007||Oct 30, 2012||The Boeing Company||Method and apparatus for locating objects using radio frequency identification|
|US8325097||Jan 16, 2007||Dec 4, 2012||Research In Motion Rf, Inc.||Adaptively tunable antennas and method of operation therefore|
|US8334703 *||Nov 20, 2008||Dec 18, 2012||Roiksimt||Apparatus for remote detection and monitoring of concealed objects|
|US8405563||Feb 24, 2012||Mar 26, 2013||Research In Motion Rf, Inc.||Adaptively tunable antennas incorporating an external probe to monitor radiated power|
|US8421548||Nov 16, 2011||Apr 16, 2013||Research In Motion Rf, Inc.||Methods for tuning an adaptive impedance matching network with a look-up table|
|US8428523||Jun 24, 2011||Apr 23, 2013||Research In Motion Rf, Inc.||Tuning matching circuits for transmitter and receiver bands as a function of transmitter metrics|
|US8432234||Jan 12, 2011||Apr 30, 2013||Research In Motion Rf, Inc.||Method and apparatus for tuning antennas in a communication device|
|US8447472 *||Jan 16, 2007||May 21, 2013||Ford Global Technologies, Llc||Method and system for impact time and velocity prediction|
|US8451162 *||Dec 19, 2006||May 28, 2013||Walleye Technologies, Inc.||Microwave datum tool|
|US8451936||Oct 22, 2009||May 28, 2013||Freescale Semiconductor, Inc.||Method and system for performing distance measuring and direction finding using ultrawide bandwidth transmissions|
|US8457569||May 31, 2012||Jun 4, 2013||Research In Motion Rf, Inc.||Hybrid techniques for antenna retuning utilizing transmit and receive power information|
|US8463218||Mar 5, 2010||Jun 11, 2013||Research In Motion Rf, Inc.||Adaptive matching network|
|US8463361||May 23, 2008||Jun 11, 2013||Lifewave, Inc.||System and method for non-invasive instantaneous and continuous measurement of cardiac chamber volume|
|US8472888||Aug 25, 2009||Jun 25, 2013||Research In Motion Rf, Inc.||Method and apparatus for calibrating a communication device|
|US8558633||Mar 21, 2012||Oct 15, 2013||Blackberry Limited||Method and apparatus for adaptive impedance matching|
|US8564381||Aug 25, 2011||Oct 22, 2013||Blackberry Limited||Method and apparatus for adaptive impedance matching|
|US8594584||May 16, 2011||Nov 26, 2013||Blackberry Limited||Method and apparatus for tuning a communication device|
|US8620236||Sep 21, 2010||Dec 31, 2013||Blackberry Limited||Techniques for improved adaptive impedance matching|
|US8620246||Nov 10, 2011||Dec 31, 2013||Blackberry Limited||Adaptive impedance matching module (AIMM) control architectures|
|US8620247||Nov 10, 2011||Dec 31, 2013||Blackberry Limited||Adaptive impedance matching module (AIMM) control architectures|
|US8624776 *||Aug 29, 2008||Jan 7, 2014||Raymarine Uk Limited||Digital radar or sonar apparatus|
|US8626083||May 16, 2011||Jan 7, 2014||Blackberry Limited||Method and apparatus for tuning a communication device|
|US8655286||Feb 25, 2011||Feb 18, 2014||Blackberry Limited||Method and apparatus for tuning a communication device|
|US8674783||Mar 12, 2013||Mar 18, 2014||Blackberry Limited||Methods for tuning an adaptive impedance matching network with a look-up table|
|US8680934||Nov 3, 2010||Mar 25, 2014||Blackberry Limited||System for establishing communication with a mobile device server|
|US8686891 *||Oct 31, 2008||Apr 1, 2014||Robert Bosch Gmbh||Locating device|
|US8693963||Jan 18, 2013||Apr 8, 2014||Blackberry Limited||Tunable microwave devices with auto-adjusting matching circuit|
|US8712340||Feb 18, 2011||Apr 29, 2014||Blackberry Limited||Method and apparatus for radio antenna frequency tuning|
|US8731333||Apr 6, 2011||May 20, 2014||Jeffrey M. Sieracki||Inspection of hidden structure|
|US8744384||Nov 23, 2010||Jun 3, 2014||Blackberry Limited||Tunable microwave devices with auto-adjusting matching circuit|
|US8779965 *||Dec 17, 2010||Jul 15, 2014||L-3 Communications Cyterra Corporation||Moving-entity detection|
|US8781417||May 3, 2013||Jul 15, 2014||Blackberry Limited||Hybrid techniques for antenna retuning utilizing transmit and receive power information|
|US8787845||May 29, 2013||Jul 22, 2014||Blackberry Limited||Method and apparatus for calibrating a communication device|
|US8798555||Dec 4, 2012||Aug 5, 2014||Blackberry Limited||Tuning matching circuits for transmitter and receiver bands as a function of the transmitter metrics|
|US8803631||Mar 22, 2010||Aug 12, 2014||Blackberry Limited||Method and apparatus for adapting a variable impedance network|
|US8860525||Apr 20, 2011||Oct 14, 2014||Blackberry Limited||Method and apparatus for managing interference in a communication device|
|US8860526||Apr 20, 2011||Oct 14, 2014||Blackberry Limited||Method and apparatus for managing interference in a communication device|
|US8872674||Mar 14, 2013||Oct 28, 2014||Balu Subramanya||Directional speed and distance sensor|
|US8878697||May 4, 2012||Nov 4, 2014||Balu Subramanya||Directional speed and distance sensor|
|US8896391||Jan 18, 2013||Nov 25, 2014||Blackberry Limited||Tunable microwave devices with auto-adjusting matching circuit|
|US8903669||Jul 16, 2009||Dec 2, 2014||The Boeing Company||Multi-band receiver using harmonic synchronous detection|
|US8942657||May 8, 2013||Jan 27, 2015||Blackberry Limited||Adaptive matching network|
|US8948889||Jun 1, 2012||Feb 3, 2015||Blackberry Limited||Methods and apparatus for tuning circuit components of a communication device|
|US8957742||Feb 8, 2013||Feb 17, 2015||Blackberry Limited||Methods for tuning an adaptive impedance matching network with a look-up table|
|US9002427||Mar 30, 2010||Apr 7, 2015||Lifewave Biomedical, Inc.||Apparatus and method for continuous noninvasive measurement of respiratory function and events|
|US9019150||Feb 20, 2012||Apr 28, 2015||TransRobotics, Inc.||System and method for sensing distance and/or movement|
|US9020446||Jun 24, 2014||Apr 28, 2015||Blackberry Limited||Method and apparatus for calibrating a communication device|
|US9024816 *||Dec 30, 2013||May 5, 2015||Raymarine Uk Limited||Digital radar or sonar apparatus|
|US9026062||Oct 10, 2009||May 5, 2015||Blackberry Limited||Method and apparatus for managing operations of a communication device|
|US9040920||Jan 2, 2013||May 26, 2015||The Boeing Company||Optical object detection system|
|US9063232||Feb 24, 2009||Jun 23, 2015||L-3 Communications Security And Detection Systems, Inc||Moving-entity detection|
|US9078582||Sep 27, 2011||Jul 14, 2015||Lifewave Biomedical, Inc.||Fetal monitoring device and methods|
|US20040123473 *||Dec 11, 2003||Jul 1, 2004||Irwin Industrial Tool Company||Laser line generating device|
|US20040249257 *||Jun 4, 2003||Dec 9, 2004||Tupin Joe Paul||Article of manufacture for extracting physiological data using ultra-wideband radar and improved signal processing techniques|
|US20040249258 *||Jun 4, 2003||Dec 9, 2004||Tupin Joe Paul||System and method for extracting physiological data using ultra-wideband radar and improved signal processing techniques|
|US20050043039 *||Aug 12, 2004||Feb 24, 2005||Yoshiji Ohta||Position detecting system, and transmitting and receiving apparatuses for the position detecting system|
|US20050078030 *||Mar 26, 2004||Apr 14, 2005||Fujitsu Limited||Pulse radar apparatus|
|US20050099330 *||Nov 24, 2004||May 12, 2005||Safe Zone Systems, Inc.||Object detection method and apparatus|
|US20050104764 *||Nov 16, 2003||May 19, 2005||Jerry Young||Portable proximity-sensing safety device|
|US20050194959 *||Mar 4, 2004||Sep 8, 2005||Zircon Corporation||Ratiometric stud sensing|
|US20050253597 *||May 14, 2004||Nov 17, 2005||Zircon Corporation||Auto-deep scan for capacitive sensing|
|US20050254354 *||Jun 14, 2005||Nov 17, 2005||Time Domain Corporation||System and method for information assimilation and functionality control based on positioning information obtained by impulse radio means|
|US20060000100 *||Mar 11, 2005||Jan 5, 2006||Gem Temp, Llc.||Printing device including stud finder for installing gem electrical outlet box|
|US20080172156 *||Jan 16, 2007||Jul 17, 2008||Ford Global Technologies, Inc.||Method and system for impact time and velocity prediction|
|US20100328137 *||Oct 31, 2008||Dec 30, 2010||Reiner Krapf||Locating device|
|US20110102244 *||Aug 29, 2008||May 5, 2011||Raymarine Uk Limited||Digital radar or sonar apparatus|
|US20130113647 *||Dec 17, 2010||May 9, 2013||L-3 Communications Cyterra Corporation||Moving-entity detection|
|US20130222172 *||Feb 27, 2013||Aug 29, 2013||L-3 Communications Cyterra Corporation||Determining penetrability of a barrier|
|US20140320336 *||Dec 30, 2013||Oct 30, 2014||Raymarine Uk Limited||Digital radar or sonar apparatus|
|USRE42840||Aug 13, 2002||Oct 18, 2011||Toto, Ltd.||Stool flushing device|
|USRE44634||May 4, 2010||Dec 10, 2013||Multispectral Solutions, Inc.||Ultra-wideband receiver and transmitter|
|USRE44998||Mar 9, 2012||Jul 8, 2014||Blackberry Limited||Optimized thin film capacitors|
|CN100390549C||Oct 15, 2003||May 28, 2008||财团法人工业技术研究院||Electromagnetic field sensing element and its apparatus|
|DE10345565B4 *||Sep 29, 2003||Aug 14, 2013||Fujitsu Ltd.||Impulsradarvorrichtung|
|DE10345565B8 *||Sep 29, 2003||Oct 31, 2013||Fujitsu Ltd.||Impulsradarvorrichtung|
|EP0783058A2 *||Dec 19, 1996||Jul 9, 1997||Steinel AG||Control device for a urinal or the like|
|EP0799428A1 *||Dec 19, 1995||Oct 8, 1997||The Regents Of The University Of California||An impulse radar with swept range gate|
|EP0901642A1 *||May 5, 1997||Mar 17, 1999||The Regents Of The University Of California||Pulse homodyne field disturbance sensor|
|EP1522872A1 *||Mar 8, 2004||Apr 13, 2005||Fujitsu Limited||Pulse radar apparatus|
|WO1998003840A1 *||Jul 23, 1997||Jan 29, 1998||Teleflex Inc||Microprocessor based apparatus and method for sensing fluid level|
|WO1998023867A1||Nov 26, 1997||Jun 4, 1998||Case Corp||Method and apparatus for sensing piston position|
|WO1999053616A1 *||Apr 14, 1999||Oct 21, 1999||Robson David John||Monopulse generator|
|WO2003019207A1 *||Aug 22, 2002||Mar 6, 2003||Rhino Analytics L L C||Ultra-wide band pulse dispersion spectrometry method and apparatus providing multi-component composition analysis|
|WO2008134074A1 *||Apr 30, 2008||Nov 6, 2008||Blin Guillaume||Techniques for antenna retuning utilizing transmit power information|
|U.S. Classification||324/642, 342/27, 342/22, 324/67|
|International Classification||G01N22/00, G01S13/88, H04B1/7163, G01S7/285, G01S13/10, G01V3/12, G01S13/93, G01F23/284, H04B1/26, G01S13/18, G08G1/04, G01S13/02, G01S13/00, G01S5/06, G01S13/04|
|Cooperative Classification||G01F23/284, G01S5/06, G01S13/003, G01S13/04, G01S13/0218, G01S13/0209, G01S13/106, G01V3/12, G01S2013/9314, G01S7/285, G01S13/103, H04B1/71637, G01S13/885, G01S13/18, G08G1/04, G01S2013/9321, H04B1/7163|
|European Classification||H04B1/7163E, G01S13/04, G08G1/04, G01S13/18, G01S7/285, G01S13/00B, G01F23/284, G01S13/02H, G01S13/02B, G01V3/12|
|May 7, 1993||AS||Assignment|
Owner name: REGENTS OF THE UNIVERSITY OF CALIFORNIA, THE, CALI
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MC EWAN, THOMAS E.;REEL/FRAME:006542/0550
Effective date: 19930506
|Nov 2, 1998||FPAY||Fee payment|
Year of fee payment: 4
|Jan 14, 2002||AS||Assignment|
|Jan 24, 2003||FPAY||Fee payment|
Year of fee payment: 8
|Nov 17, 2006||FPAY||Fee payment|
Year of fee payment: 12
|Jun 23, 2008||AS||Assignment|
Owner name: LAWRENCE LIVERMORE NATIONAL SECURITY LLC, CALIFORN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:THE REGENTS OF THE UNIVERSITY OF CALIFORNIA;REEL/FRAME:021217/0050
Effective date: 20080623